Anti-wrinkle cycle dryer with slow rotation



Jan 30, 1968 b. F. EPPLEY ANTI-WRINKLE CYCLE DRYER WITH SLOW ROTATION Filed June 1, 1966 510/704 02y ZZZZ OFF 49-52 01v OFF OFF 4 7- 48 0 01V OFF 49-5/ OFF a 0 J4-5 a 0 on:

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00/1/4140 1? [Paar United States Patent 3,365,809 ANTI-WRINKLE CYCLE DRYER WITH SLOW ROTATION Donald F. Eppley, St. Joseph, MiClL, assignor to Whirlpool Corporation, Benton Harbor, Mich, a corporation of Delaware Filed June 1, 1966, Ser. No. 554,465 10 Claims. (Cl. 3412) The present invention relates to an improved automatic clothes dryer and, more specifically, is directed to a method and apparatus for minimizing or inhibiting the setting of wrinkles in fabrics during drying by continuously tumbling the clothes after termination of the normal drying cycle at drum rotational speeds substantially lower than those employed during the normal drying cycle.

One of the objects of the present invention is to provide an improved method for drying clothes to prevent deep set wrinkles wherein the clothes are continuously tumbled at slow speeds during an anti-wrinkle cycle which follows the normal drying cycle.

A further object of the invention is to provide an improved method for preventing deep set wrinkles in clothes which avoids the additional wear imposed on belts, motor and bearings subjected to intermittent, repeated energization of the drive means.

A further object of the invention is to provide an improved clothes dryer with means for automatically shifting from a normal programmed drying cycle to an anti-wrinkle cycle wherein the clothes are tumbled at a very slow rotational speed.

Still another object of the invention is to provide an improved clothes dryer in which means are provided for tumbling the clothes at the completion of the normal drying cycle in an anti-wrinkle cycle, with termination of the anti-wrinkle cycle being dependent either upon opening the access door to the dryer, or automatically at the conclusion of a predetermined time interval.

Other objects and features of the present invention will become apparent to those skilled in the art from the following description of the attached sheet of drawings which illustrates one embodiment of the invention.

In the drawings:

FIGURE 1 is a view in elevation of a dryer assembly embodying the principles of the present invention, with portions thereof broken away to illustrate the interior construction more completely;

FIGURE 2 is a fragmentary view in elevation of the drive means as seen from the right side of the assembly of FIGURE 1;

FIGURE 3 is a circuit diagram of a control system which can be used in accordance with the present invention;

FIGURE 4 is a chart illustrating the positions of the switches shown in FIGURE 3 during various phases of the operation; and

FIGURE 5 is a fragmentary view of a selector switch which is associated with the timer mechanism to automatically convert the machine from the normal drying cycle to the anti-wrinkle cycle.

As shown in the drawings:

In FIGURE 1, reference numeral indicates generally a clothes dryer housed within a cabinet 11. A shaft 12 supports a rotatable, perforated drum 13 for rotation within the cabinet 11.- The heating elements for the dryer are enclosed within a heater box 14 in which there is provided an inlet 16 for drawing outside air therethrough. A heating element which may be an electrical resistance element 17 warms the air passing through the heater box 14, whereupon the heated air is discharged through a discharge opening 18 into the clothes being tumbled within the drum 13. While the particular showing of FIGURE 1 involves the use of an electrical heating element 17, it should be recognized that the principles of the present invention are equally applicable to a gas heated dryer wherein the electrical heating element 17 would be replaced by a gas manifold and an electrically operated igniter or standing pilot.

A blower 19 provides for circulation of heated air through the assembly, serving to move the air in the direction indicated by the arrows of FIGURE 1, and ultimately discharging it through a discharge opening 21 provided in the cabinet 11. The blower 19 includes a shaft 22 driven by means of a belt 23 from a pulley 24 mounted on a motor shaft 26. As best evidenced in FIGURE 2, a second pulley 27 is also mounted on the shaft 26, and drives a belt 28 which is trained around the drum 13 to provide for rotation of the drum during the normal drying cycle.

With conventional machines, of the type used for household laundry equipment, the drum 13 is driven at a speed of about 44 to 50 rpm. during the normal drying cycle.

As shown in FIGURE 2, the shaft 26 is driven by a motor 29 which controls the rotation of the drum 13 during the normal drying cycle. The shaft 26 extends through both ends of the motor 29, at one end carrying the pulley 24, While the other end of the shaft 26 carries pulley 27 and is coupled to a oneway clutch 31. Also coupled to the clutch 31 is a shaft 32 driven by a slow speed auxiliary motor 33 which may be of the shaded pole gear type. The clutch 31 operates such that when the motor 29 is energized, and the motor 33 is deenergized, the shaft 32 of motor 33 is not rotated. Under these conditions, the drum 13 rotates at the normal speed of approximately 44 to 50 r.p.m. On the other hand, when motor 33 is energized and motor 29 is deenergized, the shaft 32 rotates and, through clutch 31, picks up shaft 26 to thereby cause rotation of the pulley 27 and consequently drives the drum 13 at a slow speed, on the order of l to 5 rpm. This speed is not entirely critical, but the best results have been derived through use of rotational speeds in this range.

The electrical circuit for the improved dryer of the present invention is represented in FIGURE 3 of the drawings. Input .line voltage is applied to the circuitry at a pair of terminals 36 and 37. A switch 38 having a movable switch arm 39 arranged to engage a contact 41 is included as part of the access door to the dryer so that whenever the door is closed, the switch arm 39 engages the contact 41. An on-off switch 42 of the momentary contact type is provided to initiate the operation of the dryer.

A timer motor 43 operates a pair of cams 44 and 46 to provide the programmed cycle of normal clothes drying, followed by the anti-wrinkle cycle. The cam 44 operates on a switch arm 47 to cause the same to engage a contact 48, while the cam 46 operates on a switch arm 49 of a single pole double throw switch to cause the arm 49 to selectively engage either a contact 51 or a contact 52.

The circuit also includes a relay 53 operating a switch arm 54 such that when the arm 54 engages its associated contact 56, a holding circuit is established so that the onofi button 42 can be released without deenergizing the circuitry. It will be apparent that the relay 53 could be eliminated and its function maintained by replacing the relay operated switch arm 54 and contact 56 by a centrifugal switch operated by motor 29. In such an embodiment, the centrifugal switch would close soon after pressing pushbutton switch 42 to provide the necessary holding circuit.

The remainder of the circuit includes a motor 29 which is selectively energized by operation of the switch arm 49, the electrical heating element 17, and the auxiliary motor 33.

The cams 44 and 46 of the timer motor assembly are initially positioned by rotation of a selector switch generally indicated at reference numberal 57 in the drawings. A pointer 58 on the selector switch 57 is arranged to be positioned along its scale to select drying times, for example, in the range from O to 120 minutes.

When clothing is loaded into the drum 13, and the door is closed, thus closing the switch 38, the operator selects the desired drying time by moving the selector switch 57 to the appropriate point on the scale. This action causes the switch arm 47 to engage the contact 48, and the switch arm 49 to engage the contact 52. When the pushbutton switch 42 is momentarily closed, the relay coil 53 is energized, thereby bringing the switch arm 54 into contact with the contact 56 to establish a holding circuit for the relay. At the same time, the motor 29 is energized, and a normal, timed drying cycle commences,

When the timing motor 43 has advanced the selector switch 57 to the position on the dial, the cam 46 acts to move the switch arm 49 from engagement with the contact 52 to engagement with the contact 51. This movement of the switch causes deenergization of the heater 17 and the motor 29. Simultaneously, however, the antiwrinkle cycle is commenced due to the energization of the motor 33, the switch arm 47 still engaging the contact 48. The motor 33 thereupon drives the shaft 32, and, through the clutch 31, drives the shaft 26 at a slow, continuous rotational speed. During the anti-wrinkle cycle, the operator can terminate fiufiing of the clothes at any time by opening the door and thereby opening the switch 38. The opening of this switch causes the relay coil 53 to become deenergized and thereby disengages switch arm 54 from its contact 56. When the door is again closed, the motor 33 will not be reenergized because of the open circuit at the holding contacts, and thus the cycle will have been completed.

It is not desirable to permit the drum 13 to rotate slowly for indefinitely long periods, so that the timer motor is arranged to terminate the fiutfing cycle after a predetermined time interval has elapsed. Thus, when the selector switch 57 has rotated to the off position, the cam 44 causes the switch arm 47 to be disengaged from the contact 48, thereby opening the circuit to the relay coil 53 and also to the motor 33.

From the foregoing it will be understood that the method and apparatus of the present invention provide an anti-wrinkle cycle which can be automatically inserted into the normal programmed operation of a clothes dryer to prevent the setting of deep wrinkles in the fabrics after the conclusion of the normal drying cycle. It should be understood, also, that the normal drying cycle as referred to herein may include a cool down period in which the drum still rotates at the relatively high velocity, but at which the heating means is deenergized prior to the expiration of the times set on the selector switch.

It should also be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of inhibiting the setting of wrinkles in fabrics during drying which comprises continually tumbling said fabrics at a first normal speed throughout a clothes drying period, terminating the tumbling at said first normal speed upon completion of said clothes drying period, and

thereafter continuously tumbling said fabrics at a control means including means for energizing said drive means at said first speed throughout a clothes drying period, and

means for energizing said drive means at said second slower speed at the conclusion of said clothes drying period.

4. A clothes dryer comprising a rotatable drum,

drive means for rotating said drum at a first speed and a second slower speed, control means including first switch means for energizing said drive means at said first speed throughout a clothes drying period, second switch means for energizing said drive means at said second slower speed at the conclusion of said clothes drying period, and timer means for operating said second switch means to deenergize said drive means after a predetermined time period following said clothes drying period.

5. A clothes dryer comprising a rotatable drum,

first drive means arranged to rotate said drum at a substantially constant predetermined speed,

timer means arranged to energize said first drive means for a preselected time interval to thereby tumble the contents of said drum during said interval,

a second drive means arranged to drive said drum at a substantially constant predetermined speed substantially less than said predetermined speed atwhich said first drive means rotates said drum, and

switch means operated by said timer means and selectively transferring rotation of said drum from said first drive means to said second drive means at the completion of said preselected time interval.

6. The clothes dryer of claim 5 in which said timer means is arranged to terminate energization of said second drive means after expiration of a predetermined time interval.

7. A clothes dryer comprising:

a rotatable drum having an access ing fabrics to be dried,

a door covering said access opening,

first drive means for rotating said drum at a first speed,

second drive means for rotating said drum at a second speed which is substantially less than said first speed, and

control means including, first control means for energizing said first drive means throughout a clothes drying period, and second control means for energizing said second drive means at the completion of said clothes drying period.

8. The clothes dryer of claim 7 in which said second control means includes a door operated switch means for terminating the operation of said second drive means upon opening of said door.

9. The clothes dryer of claim 7 in which said first drive means and said second drive means each includes opening for insert- 6 a motor, and the two motor s are interconnected through References Cited i g ig 1"? cg f 1 7 h d d UNITED STATES PATENTS e c 0 er 0 c mm W erem sa1 secon control means irfc lud s a timer, and a switch means op- 3112;; erated by said timer for terminating the energization of 5 3i286:364 11/1966 Morrison 34 45 said second drive means upon expiration of a predetermined time interval. KENNETH W. SPRAGUE, Primary Examiner. 

1. THE METHOD OF INHIBITING THE SETTING OF WRINKLES IN FABRICS DURING DRYING WHICH COMPRISES CONTINUALLY TUMBLING SAID FABRICS AT A FIRST NORMAL SPEED THROUGHOUT A CLOTHES DRYING PERIOD, TEMINATING THE TUMBLING AT SAID FIRST NORMAL SPEED UPON COMPLETION OF SAID CLOTHES DRYING PERIOD, AND THEREAFTER CONTINUOUSLY TUMBLING SAID FABRICS AT A SECOND SPEED SUBSTANTIALLY SLOWER THAN SAID FIRST SPEED TO THEREBY PRECLUDE THE FORMATION OF WRINKLES IN SAID FABRICS. 